Java 比较 JUnit 断言中的数组，简洁的内置方式？
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Comparing arrays in JUnit assertions, concise built-in way?
提问by mBria
Is there a concise, built-in way to do equals assertions on two like-typed arrays in JUnit? By default (at least in JUnit 4) it seems to do an instance compare on the array object itself.
是否有一种简洁的内置方法可以对 JUnit 中的两个类似类型的数组进行 equals 断言？默认情况下（至少在 JUnit 4 中）它似乎对数组对象本身进行实例比较。
EG, doesn't work:
EG，不起作用：
int[] expectedResult = new int[] { 116800, 116800 };
int[] result = new GraphixMask().sortedAreas(rectangles);
assertEquals(expectedResult, result);
Of course, I can do it manually with:
当然，我可以通过以下方式手动完成：
assertEquals(expectedResult.length, result.length);
for (int i = 0; i < expectedResult.length; i++)
assertEquals("mismatch at " + i, expectedResult[i], result[i]);
..but is there a better way?
..但是有更好的方法吗？
采纳答案by Andy Thomas
Use org.junit.Assert's method assertArrayEquals:
使用org.junit.Assert的方法assertArrayEquals：
import org.junit.Assert;
...
Assert.assertArrayEquals( expectedResult, result );
If this method is not available, you may have accidentally imported the Assert class from junit.framework.
如果此方法不可用，您可能不小心从junit.framework.
回答by Bozho
You can use Arrays.equals(..):
您可以使用Arrays.equals(..)：
assertTrue(Arrays.equals(expectedResult, result));
回答by Michael Brewer-Davis
回答by Haroldo_OK
I know the question is for JUnit4, but if you happen to be stuck at JUnit3, you could create a short utility function like that:
我知道这个问题是针对 JUnit4 的，但如果你碰巧被 JUnit3 卡住了，你可以创建一个像这样的简短实用函数：
private void assertArrayEquals(Object[] esperado, Object[] real) {
assertEquals(Arrays.asList(esperado), Arrays.asList(real));
}
In JUnit3, this is better than directly comparing the arrays, since it will detail exactly which elements are different.
在 JUnit3 中，这比直接比较数组要好，因为它会详细说明哪些元素不同。
回答by csharpfolk
I prefer to convert arrays to strings:
我更喜欢将数组转换为字符串：
Assert.assertEquals(
Arrays.toString(values),
Arrays.toString(new int[] { 7, 8, 9, 3 }));
this way I can see clearly where wrong values are. This works effectively only for small sized arrays, but I rarely use arrays with more items than 7 in my unit tests.
这样我就可以清楚地看到错误的值在哪里。这仅适用于小型数组，但我很少在单元测试中使用项目数超过 7 的数组。
This method works for primitive types and for other types when overload of toStringreturns all essential information.
当重载toString返回所有基本信息时，此方法适用于原始类型和其他类型。
回答by winstanr
Using junit4 and Hamcrestyou get a concise method of comparing arrays. It also gives details of where the error is in the failure trace.
使用 junit4 和Hamcrest，您可以获得比较数组的简洁方法。它还提供了错误在故障跟踪中的位置的详细信息。
import static org.junit.Assert.*
import static org.hamcrest.CoreMatchers.*;
//...
assertThat(result, is(new int[] {56, 100, 2000}));
Failure Trace output:
故障跟踪输出：
java.lang.AssertionError:
Expected: is [<56>, <100>, <2000>]
but: was [<55>, <100>, <2000>]
